Re: [PATCH 0/1] Implement /dev/byte (a generic byte source similiarto /dev/zero)

From: Alexander Holler
Date: Tue Apr 19 2011 - 04:34:20 EST


Am 18.04.2011 15:57, schrieb Mike Frysinger:
On Mon, Apr 18, 2011 at 07:37, Alexander Holler wrote:
I don't know if this patch qualifies for inclusion into the mainline kernel, but
maybe someone else would be interested in such, so I'm posting it here.

The main idea for that device was to have a source for 0xff to clear FLASH based
devices. And to make it more generic, I've added the possibility to change the
default value on a per file descriptor basis.

I don't want to discuss if such a device makes sense or if such should be done
in userspace only. I like it as a device, otherwise I wouldn't have written it.
So besides this message, I will not take part in such a discussion.

cant you do this with cuse ? that would satisfy the "has to be a
device" requirement while keeping it in userspace.

I know almost nothing about cuse, but I assume it should be possible to build such a device with cuse too.

although, i have a hard time seeing there be a realistic perf diff with:
tr '\000' '\377'< /dev/zero | dd ......

There are many other ways to achieve such in userspace (even without using /dev/zero) and I want to avoid such a discussion.

As for /dev/zero there are many other possible reasons to use such a device, besides filling something with a value. For me it's as reasonable as dev/zero, just that it offers a bit more flexibility and provides another, at least for me useful, default value. Maybe /dev/nzero would have been a good name too. ;)

But I don't really care about inclusion into the kernel, it's just something I had lying around (and needed only marginally work to finalize as a proper patch) and I thought someone else could find it usefull and I should share that here.

Regards,

Alexander Holler
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